Determination of the Three-dimensional Structure of Gynoside A in Solution using NMR and Molecular Modeling

Abstract

The three-dimensional structure of Gynoside A, an ocotillone-type triterpenoid glycoside isolated from Gynostemma pentaphyllum, was determined in pyridine-d5 and DMSO-d6 solution through constrained molecular modeling using constraints derived from proton NMR spectra. The calculation yielded well-defined global minima. Except for some quantitative details the overall structure of Gynoside A in pyridine-d5 shared many common features with that in DMSO-d6. The structure in pyridine-d5 had lower energies than that in DMSO-d6 solution.

Keywords

• NMR
• Gynoside A
• triterpenoid glycoside
• molecular modeling